Optimized Algorithm Of Multi-AUV Cooperative Navigation System And Design Of Its Formation Configuration

The development of ocean is a hotspot nowadays,and it needs many kinds of high-tech methods to understand and develop the ocean.As one of the important methods,Autonomous Underwater Vehicle(AUV)has been paid increasing attentions nowadays.High precision navigation and positioning of AUVs is the premise and guarantee for AUVs to complete various tasks,and cooperative navigation is an effective method of accurate navigation for multi-AUV system.In this paper,aiming at multi-AUV cooperative navigation system,the optimization algorithm and formation configuration have been studied.The main contents are as follows.1.Firstly,the concept and features of multi-AUV cooperative navigation is introduced in detail under the background of single master multi-AUV cooperative navigation system.Then the coordinate systems which are commonly used in navigation system and their relationships are described,and the commonly used AUV motion parameters are defined.Then the sensors used in cooperative navigation system have been introduced in details.Finally,the fundamental of multi-AUV cooperative navigation system is introduced.2.Based on the state-space method and kinematical equation of AUV,the mathematical model of single master multi-AUV cooperative navigation system is built,and cooperative navigation algorithms which are fit for the processing of the model have been discussed deeply.The Extended Kalman Filtering(EKF),the Simplex Sampling Unscented Kalman Filtering(SSUKF)and the Cubature Kalman Filtering(CKF)have been introduced detailedly,and their analysis and derivation have been proceeded,respectively,then simulation of the application of above algorithms in single master multi-AUV cooperative navigation system have been carried out compared by their calculation amount and accuracy.3.Based on the single master multi-AUV cooperative navigation system mode,as well as extend it into more masters mode,study the optimized formation configuration of multi-AUV cooperative navigation system on basis of two theories: the observability and the extreme value of Cramer-Rao inequality lower bound,the optimal formation has been analyzed,and the optimized formation of single master,double masters,adding more master/slave AUVs have been studied,the value of Cramer-Rao inequality lower bound is calculated,and finally come up with the design of multi-AUVs cooperative navigation system's optimal topology formation configuration under different conditions.4.For the above mentioned three single mater multi-AUV cooperative navigation algorithms together: EKF,SSUKF and CKF,the single master cooperative navigation simulation experiments has been designed,respectively.By analyzing the experimental results,the characteristics in navigation accuracy and system stability of three kinds of algorithms are discussed.Then by increasing the number of master AUV,the simulation test and verify of the cooperative navigation accuracy have been made under different formation to prove the correctness of the designed optimized formation.At last,an actual experiment of double master multi-AUV cooperative navigation has been carried out,and by analyzing the experimental data,the relationship of formation and navigation accuracy is verified,and the designed optimal formation configurations is proved.